Automatic choker for carburetors



March 23,1926 1,577,7 5

' G. R. SISSON 1 AUTOMATIC CHOKER FOR CARBURETORS Filed April 25, 1923INVENTOR. 62: R. 5/550/V,

By IL A TTORNE Y.

Patented Mar. 23, 19 26. I UNITED STATES PATENT OFFICE.

GLEN n. SISSON, F PENDLETON, INDIANA.

AUTOMATIC CHOKER FOR CARBURETORS.

Application filed April 25, 1923. Serial No. 634,576.

, of which the following is a specification.

It is the object of my invention to provide an automatic choker forcarburetors, for regulating the air-supply, especially during starting,so that an efiicient mixture under both starting and operatingconditions ma be obtained without requiring special I skil on the partofthe operator.

In the operation of automobiles, drivers have difiiculty, afterstarting, in getting the right amount of air. They may fail to start byhaving too much air. They may fail to start by having too little air.They are apt to have inefiicient 2 many especially in and just operationafter starting by reason of too little air, on account of keeping thechoker 'closed too long; although many operators kill their engineimmediately after starting by opening the chokervalve too wide beforethe engine is heated up, thus permitting too large an air supply for acold engine.

In accordance with my invention, I control a supply of air by theoperation of the starter motor, so that while the starter motor is inoperation this supply of air will be largely or wholly shut off. Ipreferably arrange this air-supply which is thus controlled by theoperation of the starting motor so that it is one of two supplies,leading to the carburetor in parallel; and preferably control the secondair-supply by a thermostatic device, responsive as shown to thetemperature of the engine in some suitable way, so that such secondair-supply is opened more widely as the temperature of the engine rises.My invention contemplates various combinations of less than allthesefeatures, as the claims set forth.

The accompanying drawing illustrates my invention: Fig. 1 is a sideelevation of an automobile engine equipped with my invention, thestructure being shown semidiagrammatically; and Fig. 2' is an enlargedelevation of-the controlling means for the air-supply.

The enginelO is supplied with explosive mixture by the usual carburetor11, which supplies such explosive mixture to the engine through anyconvenient intake manifold 12; andthe exhaust gases from the engine aredischarged through an exhaust manifold 13 in the usual way. At leastpart of the air intake forthe carburetor 11 is conveniently derived fromthe usual stove 15 on the exhaust manifold 13, so that the air will beheated by the heat of the exhaust gases, though this stove is notessential to my invention.

The air-supply pipe 16 for the carburetor 11 has two branches 17 and 18,both of which join into the pipe 16 and communicate therethrough withthe carburetor 11. These two branches are both shown as deriving theirair from the stove 15, though that is not essential. I have shown thetwo pipes 17 and 18 merely diagrammatically, without intending toindicate any definite relation as to their relative sizes. The relationbetween these two pipes may be varied .as desired.

In the branch-pipe 17 is a choker valve 20, which is normallyspring-pressed to the open position shown but is arranged to be closedwhen the circuit of the starter motor 21 is closed. The starter motor 21is supplied with current from the usual battery 22; and

is controlled by the usual foot-switch 23,

which when depressed closes the circuit of such starter motor. Thecontrolling device for'the choker valve 20 is shown as a solenoid 24connected in shunt to the starter motor 21, so that it is controlled incommon with such starter motor by the foot-switch 23; which solenoid 24has a core 25 suitably connected to an operating arm 26 of the chokervalve 20. A spring 27 or other returning device holds the choker valve20 normally in open position, but when the solenoid 24 is energized thechoker valve 20 is moved to closed position to shut ofl the supply ofair to the carburetor through the branch pipe 17.

Thus when the foot-switch 23 is closed to complete the circuit for thestarter motor 21, and such-starter motor is operating to turn over theengine 10, the air-supply through the branch pipe 17 is shut ofi' andthesupply pipe 16 of the carburetor must derive its whole supply; of airfrom the branch pipe 18. This cuts down the quantity of air delivered tothe carburetor, and thus assists in starting. As soon as the footswitch23 is released and allowed to open, both the starter motor 21 and thesolenoid 24 are de-energized, and the choker valve 20 is opened byits'spring 27, thus admitting parts are arranged as shown, courselnessentlal.

choker valve 30. I

opened and closed as the temperature of the I more air to the carburetorafter the engine is i started While the branch-pipe 18 may be valveless,I prefer to rovide vitalso with a his choker valve 30 is engine risesand falls respectively. To this on the operating arm 31 of the chokervalve 30 is connected to any suitablethermostat 32, suitably arranged tobe responsive to the temperature of the engine itself, orof somethingwhich varies in temperature with the engine. The thermostat 32 is shownas a single two-metal thermostat strip, supported at one end on theexhaust manifol 13, and connected at the other or free en" by a link33-,to the arm 31. The free end of the thermostat 32 bows upward uponincrease of temperature, and downward upon decrease of temperature, ifthe but this is of Therefore, when the engine is started cold, bothchoker valves 20 and 30 are closed, and very litle air is supplied tothe carburetor.

'As soon as the engine starts, the choker valve 20 is opened, to admitmore air; and as the ture of the engine;and the starting choking is onlyby the choker valve 20, which is opened as soon' as thexdriver releasesthe foot-switch 23. v

This makes a substantially fool-proof arrangement, requiring, no skillor care on the part of the operator to get suitable mixtures forstarting under all conditions, and for.

- varying the choking 'of the supply of air to the carburetor inaccordance with the temperature of the engine.

2. A choking device for an internal combustion engine having acarburetor and a starting device, comprising means for automaticallychoking the supply of air to the carburetor during the starting of theengine by said starting device, and additional means for choking thesupply of air to said carburetor in accordance with the temperature ofthe engine.

3. In combination, an internal combustion engine, a carburetor and astarting device therefor, said carburetor being provided supply is'soincreased.

engine, a carburetor and a starting device therefor, said, carburetorbeing provided with a branched air-inlet, and a choker valve arranged inone of said branches and controlled jointly with said starting device.5. In combination, an internal combustion engine, a carburetor and astarting device therefor, said carburetor being provided with a branchedair-inlet, a choker ,valve arranged in one of said branches andcontrolled jointl with said starting device, and a choker va v,earranged in the other of said branches and controlled'by the temperatureof the engine.

6. In combination, an internal combustion engine, a carburetor therefor,said carburetor being provided with a branched airinlet, a choker valvearranged in one of said branches, and means for controlling said chokervalve by the temperature of the engine, the other branch being free fromcontrol by the temperature of the engine.

7. A choking device for the carburetor .of'

an internal combustion engine having a starting device, comprising meanscontrol led jointly with said starting device for automaticallychokingthe supply of air to the carburetor during the starting of the engine,.1

by said starting device, and a thermostat for. varying such choking.

8; The combination set forth in claim 7, with the addition that saidthermostat is responsive to the temperature of the engine.

9. A choking device for the carburetor of an internal combustion enginehaving a starting device, comprising means controlled jointly with saidstarting device for automatically choking the supply of air to thecarburetor during the startlng of the engine creasing the chokingproduced by said choker valve upon increase in temperature of theengine.

10. A choking device for the carburetor.

no I

means being arranged to increase the air supply upon cessation of thestarting-device operation, and a thermostat for varying theproportionate extent to which such air 11, A choking device for thecarburetor of an internal combustion engine having a starting device,comprising means controlled f jointly with said starting device forauto- 110 .by said starting device, and means for de- 1 inaticallychoking the silpplyeof ai'r'to the carburetor during the startmg of theengine by said starting device, and a thermostat also exerting a control.on the choking gme.

13. The combination set forth in claim 11,

with the addition that the air-supply to the carburetor is-branched, andsaidfirst-named means and said thermostat exert their chokingactions indifferent branches of said airsupply.

In witness whereof,v I have hereunto set my hand at Indianapolis,Indiana, this 23d day of April, A. D. one thousand nine hundred andtwenty-three.

' GLEN'R. SISSON.

